Created on:2021-09-13 10:42

Construction machinery_ Maintenance of excavator_ Detection and debugging of hydraulic system after transformation

Construction machinery_ Maintenance of excavator_ Detection and debugging of hydraulic system after transformation

(1) Performance test and debugging of the whole machine after technical transformation

① After the completion of technical transformation, after no-load operation and running in, test the matching between the new hydraulic pump and the engine and the complexity of the movement speed of each part under the full load state, and adjust the new regulator to meet the full power regulation with the engine first; ② Adjust the rated movement speed of each working mechanism (new machine); ③ Verify whether the compound action control function of the original machine is correct; ④ Verify the balance mechanism of flow distribution and the correctness of oil return.

The test results show that: ① the action function, compound and pilot control of each part are correct; ② The motion speed is within the standard range of performance parameters of the new machine; ③ The slewing speed is slightly faster than that of the new machine; ④ The matching between the hydraulic pump and the engine is good, and there is no vehicle holding phenomenon in the process of full load, continuous and compound action; ⑤ The pump coupling operates stably without noise; ⑥ The hydraulic system operates stably without noise, vibration, impact and leakage; ⑦ After continuous trenching for 4h, the oil temperature on the outer wall of the oil tank of the hydraulic system was tested to be 65 ℃, and the temperature at the construction site was 33 ℃.

(2) Economic and technical analysis after technical transformation

The comparison of economic and technical analysis is shown in the table below. It can be seen from the table that the total cost of technical renovation of hydraulic system is 160000 yuan, which is only 1 / 3 of that of original parts. The new pump has advanced performance, high reliability, easy supply of accessories, low price, convenient maintenance, large flow change range and wide application.

 

Comparison table of economic and technical analysis

Serial number

部件

名称

数量

原件更新

价格/万元

 

序号

部件

名称

数量

改造更新

价格/万元

1

泵传动箱

1

15

 

1

泵链接传动装置

1

0.7

2

主液压泵

2

25

 

2

主液压泵+先导泵

1

14

3

回转泵

1

8

 

3

机械加工、配件费

1

0.3

4

先导泵

1

0.6

 

 

 

 

 

合计

5

48.6

 

合计

2

16

 

In order to cooperate with the technical transformation of the hydraulic system and make the whole machine meet the requirements of synchronous performance and life, we also repaired the whole machine and paid 150000 yuan for the repair cost, so the total cost of the technical transformation and maintenance of the whole machine is 310000 yuan. Calculated according to the rate of return on machinery leasing: the monthly rental unit price of UH181 excavator market is about 50000 yuan, and the annual working time is about 8 months, then the annual net income is 400000 yuan. Before the transformation, the evaluated value of UH181 excavator is about 200000 yuan, plus 310000 yuan of technical transformation and maintenance cost, with a total asset value of about 510000 yuan.

It is estimated that the service life of the excavator after technical transformation is 5 years. 4. The residual value of it excavator is 400000 yuan, so the annual depreciation cost is 93800 yuan; The annual repair and maintenance cost is about 25500 yuan; The annual management fee is 28000 yuan; The one-way transportation cost is 20000 yuan; The capital occupation fee is 40800 yuan. Then the annual net profit = 40-938-2.55-2.8-2-4.08 = 192000 yuan, and the annual net profit rate is 37. = 65%. The investment payback period is 2.6 years, that is, the total investment cost can be recovered in 2 years and 7 months.

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